Research and Education in Mechanical Tolerancing and Dimensional Metrology

最近的国家研究发现，在机械公差和计量标准和实践方面，以及在大学、培训机构和工业的教学方面，存在严重的缺陷。所有这些缺陷背后的核心问题是缺乏适当的机械公差的科学基础。本质上，公差和计量是从车间实践演变而来的，并且作为特殊情况技术的集合来教授和应用。该项目通过四个相关的研究方向来改善这种状况：(1)为ANSI Y14.5公差标准的主要原则开发半正式的数学法典，最初以专著和/或工程专业学生的课程笔记的形式；(2)扩展了分析几何公差累积的数学和计算技术（即一维公差叠加的推广）。这些技术在装配设计中很重要；(3)将编纂与计量实践联系起来，对尺寸和表面建模方面的开放问题进行选择性研究；(4)功能容限的探索性研究（即控制空间变异性对设计人工制品性能的影响）。

Recent national studies have identified serious deficiencies in mechanical tolerancing and metrology standards and practices, and in the teaching of these in universities, training institutes, and industry. The central problem underlying all of these deficiencies is the lack of proper scientific foundations for mechanical tolerancing. In essence, tolerancing and metrology evolved from shop-floor practice, and are taught and applied as collections of special-case techniques. This project pursues four related lines of research to improve this situation: (1) development of a semi-formal mathematical codification for the main principles of the ANSI Y14.5 tolerancing standard, initially in the form of a monograph and/or course notes for engineering students; (2) extension of the codification with mathematical and computational techniques for analyzing the accumulation of geometric tolerances (i.e., generalization of one- dimension tolerance stacking). Such techniques are important in design for assembly; (3) linking of the codification to metrology practices, with selective research on open issues in dimensional and surface modeling; and (4) exploratory research in functional tolerancing (i.e., control of the effects of spatial variability on the performance of designed artifacts).